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Research Results

Work associated with the third year of my ACS-PRF grant (PRF No. 46649-B2) has been completed.   The highlights of the research this year include a textural study of the Marcellus Shale and characterization of the mineralogy of numerous shale samples.  This work has been facilitated by the procurement of a FEI scanning electron microscope (SEM) with energy dispersive analysis (EDA) and cathodoluminescence (CL) capabilities.   The SEM was provided by a grant (PI - J. Chiarenzelli) from the National Science Foundation via the Major Research Instrument program.  An x-ray diffractometer was purchased from funds obtained from a private granting agency and used for clay mineral identification.  Two students (Wendell Caesar and David Mosher) have been supported by the grant this year.  Three student presentations, involving four students (Caesar et al., 2010; Mosher et al., 2010), related to the project were made last spring at the Northeastern Annual Meeting of the Geological Society of America in Baltimore, MD and two student presentations are planned for the fall annual Geological Society of America meeting in Denver this November.  A senior thesis entitled “Geochemical, Textural, and Isotope Study of the Devonian Marcellus Shale” was completed by David Mosher in May 2010.

Among the major conclusions are:  1) the Marcellus Shale, with the possible exclusion of the Union Springs Member, was likely deposited in relatively shallow, oxygenated water; and 2) the source of Ordovician and Devonian shales in the New York section of the Appalachian Basin likely includes a component of Archean material from the Superior Province.  The first conclusion is based on both textural and geochemical considerations and the second on Neodymium T_DM model ages which are as old as 2200 Ma requiring a provenance that includes older material.

Impact on Student Learning and Training

During the third year of the project, two undergraduate students worked closely with Dr. Chiarenzelli.  One student, David Mosher, completed a senior thesis on the geochemical and textural characteristics of the Marcellus shale. He will attend graduate school at Rensselaer Polytechnic Institute this fall. Another student, Wendell Caesar, completed a directed study on the Sm-Nd systematics of Devonian and Ordovician shales and will begin a study on shale clay mineralogy this fall.  In addition he will travel to Ottawa to begin a Sm-Nd study of Silurian shales, this fall or during winter break. Undergraduate geology major/chemistry minor John Murphy traveled to Carleton University in Ottawa this summer and completed additional analyses of the Neodymium isotopic systematics of NYS shale samples.  David Mosher worked with Dr. Neal O’Brien (SUNY Potsdam) defining the texture of the Marcellus Shale using SEM techniques. 

Changes to the Research Plan

The original research plan of the project has been modified to allow greater student participation and to match summer and academic year schedules.  For example, Dr. Chiarenzelli and his research students have focused considerable effort on local New York shales.  The Devonian Marcellus shale and Ordovician Utica shale are considered to have enormous potential for hydrocarbons, particularly natural gas.  Much of the textural work planned as part of the project is now possible because of a NSF award for a new scanning electron microscope (SEM) to Chiarenzelli.  The new SEM was installed in January and utilized to characterize the texture of the shale units studied by Dr. Chiarenzelli and his student researchers.  David Mosher and Wendell Caesar have worked closely with Dr. Neal O’Brien (SUNY Potsdam) to learn SEM preparatory techniques and how to interpret the textural features of shales.  Finally, the team has broadened their study to include a Neodymium isotopic study of Ordovician and Devonian shales with Dr. Brian Cousens at Carleton University in Ottawa.  The intent was to determine the source and possible temporal changes in the northern portion of the Appalachian Basin.  The data is exciting and has some important constraints for the provenance of these unconventional gas source rocks.  A suite of Silurian shales were collected this summer to provide more continuous stratigraphic coverage in the northern Appalachian Basin.

Dissemination of Results 

In order to disseminate the research results, presentations have been given in various venues (America Association of Petroleum Geologists and national and sectional meetings of the Geological Society of America).  More are planned for the fall annual meeting of the Geological Society of America to be held in Denver in late October. 

Future Plans

Future plans include the continuation of the project with emphasis on:  1) compilation, analysis, and presentation of our data; 2) preparation and analysis of samples from the Silurian units of New York for Sm-Nd analysis; and 3) summary of the research group’s work for various journal articles.